Antiperspirants and Alzheimer's Disease. Back in the 1960s, a few studies found high levels of aluminum in the brains of people with Alzheimer's disease. The research suddenly called into question the safety of everyday household items such as aluminum cans, antacids, and antiperspirants.
A harmonic drive apparatus comprises a circular spline which has internal spline teeth and which is rotatable around a rotational axis , a flexible cylindrical flexspline which is concentrically disposed within the circular spline and which has external spline teeth , the number of flexspline external teeth being less than the number of internal ...
A waveform with increased harmonics at higher frequencies is the result of these much faster switching devices, usually at frequencies of 10,000 to 20,000 Hertz. Drives and motors often need to be separated by significant distances. For deep wells or mines, the motors are usually controlled on the surface. As a result, the distance between the drive and the motor creates long motor lead lengths. In some plant applications, the motors can withstand the harsh environment but the sensitive variable frequency drive cannot.